Oxidation of petroleum wax



OXIDATION OF PETROLEUM WAX 2,$$3,539 Patented Aug. 20, 1957 2 to break the mixture into extract and raffinate phases For the above reasons it has not heretofore been found practicable to recycle the raffinate to the oxidation stepso as to oxidize the wax to extinction.

It is therefore an object of this invention to treat the' Bertrand W. Greenwald, Camden, N. J., assignor to Cities rafiinate from an extraction of crude wax oxidate in such Service Research and Development Company, New a manner as to recover one fraction substantially poorer York, N. Y., a corporation of New Jersey in oxygenated compouhds than the starting material suit- N0 Drawing Applicafien July 30 1953, able for recycle to the oxldizer, and a second fraction subserial 371 40g stantially richer 1n oxygenated materials, WhlCll may be 5 I recycled to the extraction step, or to some other stage 8 Claims. (0'. 260-452) of the process. It is another object of this invention to remove substantially all resinous materials from the ratfinate. This invention relates to a process for preparing oxy- I have found that the foregoing objects may be attained? genated compounds by the oxidation of petroleum wax, by adsorption of the rafiinate on active carbon, followed and more particularly to the treatment of fractions of the by a two stage desorption, using in the first stage a nonoxidized product to decrease the proportion of oxygenpolar desorbent, such as a low boiling hydrocarbon, and ated materials therein whereby to obtain a product betusing a polar desorbent, such as, for example, methyl ter suited for recycle to the oxidation step. i 29 ethyl ketone, ch1oroform, or pyridine in the second stage.' The oxidation of petroleum wax to produce fatty acids, The first stage desorbate 1s recovered and heated to drivealcohols, and ketones by air blowing at elevated temperaoverhead the desorbent, which is returned to the process, tureil, has long been known tobthe art. lrli1 order to arrive leaving gs a EOHOIIIIIS prcgluct naterlal substantially rlcherat t e esired product distri ution, wit t e minimum inpara in t ant e ra nate eed; This material may,"- production of undesirable products such as multifuncof course, if its oxygen content is still undesirably high, tional compounds, odor bodies, and resins, it is custombe subjected to one or more additional adsorption-deary to stop the oxidation when a desired neutralization sorption steps to reduce the oxygen content to the denumber has been reached, and to separate the oxy prodsired point, and may then be recycled to the oxidation step. ucts from the unoxid zed wax. ThlS separation may be It has been found that the desorbate is substantially free made by extraction with polar solvents such as lower boll- 30 of res nous materials, and that upon subsequent oxidation, mg alcohols or ketones to obtam an extract rich in oxy emulsion difficulties 1n the extract10n step are substanchemicals and raffinate rich in unoxidized wax. The tially eliminated. extract may then be treated in a conventional manner to The second stage desorbate may be freed of desorbent recover urified roducts. by conventional methods, and ma be rec cled to the The rsflinate, izhich will usually comprise about half crude oxidate extraction zone. y y of the crude oxidate, will, however, contain in addition The following table illustrates the results: obtained by to unoxidized Wax, certain quantities of oxygenated commy new process in two typical runs using as feed stocks pounds, depending on the nature of the solvent employed, railinates obtained from a methanol extraction of a crude the solvent feed ratio, and other conditions employed. wax oxidate containing about oxy compounds.

Charge 1st Desorbate 2nd Desorbate Loss Desorbents Per- Per- Per- Per- Wt., g. cent Wt., g. cent Wt., cent Wt., cent WBIX wax g. wax g.

1 H t 100 71 i fifi 12 so 15 49 7 7 so 82.5 ZEQ Q 25 as 4 so 1 3.3

Sinfie, minimize difficulties in Processing the eXtlact, Both first and second desorbates were almost water it is desirable to hold the wax content thereof 120 a minihite in color, and free from objectionable odors, Wheret lic io fi mpl g ys h fl l gt i is (in bothb runs thebrlaflirzlate charge was dark in color, and se ec v1 y or oxygena e compoun S. no so ven s o a an o j ti a e 0 r, nega ustually possess hflgh cag clt yfo tnd g igrgs l th: ll-laling now defscribed my invention, what is claimed is: Ta na 6 y @011 F0111 a 011 0 a 011 Percen process or treating a mixture of paraflin Wax of oxygenated materials. If the raflinate isthen mixed and oxygenated hydrocarbon compounds obtained as WlIh fresh Wax and recycled the Oxidation S ep, lfs rafiinate in the solvent extraction following oxidation of oxygenated content will be subjected to further oxidation, petroleum Wax which comprises, adsorbing the mixture resultmg f g of g f mhglfunctlonal on activated carbon, desorbing the carbon and adsorbed f p g foxy i i material in a first stage desorption with a low boiling, W 10 m e swsequn ex rac Ion 5 W1 pass non-polar, hydrocarbon solvent, recovering a desorbate mto the extract and contammate the products recovered from said first stage desorption and separating therefrom therefrom. Oxidation w1ll also result in the formation of a roduct oor r in OX Hated h dr a b d resins, which are insoluble in the solvents employed, and 5 P d r onbcompcgunds will build up in the raffinate, and consequently in the g e mlx esor 5 t 9 an a fresh Wax-raffinate mixture which is to be subjected to Sor e matena m secon Stage Wlth a polar further oxidation. While these resins are not extracted Solvent Selected from the q l stlng of methyl ethyl from the crude oxidate in the extraction step, and thereketone, Fhloroform and pyndmfb recovenng a fiesorbate fore do not contaminate the final product, they are unfrom 531d Second Stage desorptlon and Separating theredesirable because they tend to cause the solvent to emulsify with the crude oxidate making it very difficult from a product richer in oxygenated compounds than said original mixture.

The process according to claim 1 in which the non polar desorbent is heptane.

3. The process according to claim 1 in which the polar solvent is chloroform.

4. The process according to claim 1 in which the polar solvent is pyridine.

5. The process according to claim 1 in which the non polar solvent is heptane and the polar solvent is methyl ethyl ketone.

6. The process according to claim 1 in which the non polar solvent is heptane and the polar solvent is pyridine.

7. The process according to claim 1 in which the polar solvent is chloroform.

8. A process for treating a mixture of parafiin Wax and oxygenated hydrocarbon compounds obtained as raflinate in the solvent extraction following oxidation of petroleum wax which comprises adsorbing the mixture on activated carbon, treating the carbon and adsorbed material ina first stage desorption operation with a low boiling, non-polar, paraffinic hydrocarbon solvent having highly preferential desorbing properties for the paraifin wax in said mixture, recovering a desorbate from said first stage desorption operation, passing said desorbate to a distillation operation, withdrawing an overhead of substantially pure desorbent from said distillation operation and a paraflin wax bottoms product, recycling the desorbent overhead to the first stage desorption operation,

recycling said vparaffin wax bottoms product to further oxidation treatment, treating the carbon and adsorbed material in a second stage desorption operation with a polar desorbent selected from the group consisting of methyl ethyl ketone, chloroform, and pyridine, recovering a desorbate from said second stage desorption operation; passing said desorbate to a distillation operation, withdrawing an overhead of substantially pure desorbate from said distillation operation and a bottoms product richer in oxygenated compounds than said original mixture, recycling the desorbent overhead to the second stage desorption operation and passing the withdrawn oxygenated bottoms product to further separation treatment.

References Cited in the file of this patent UNITED STATES PATENTS 2,449,402 Lipkin et al Sept. 14, 1948 2,459,442 Lipkin Jan. 18, 1949 2,564,717 Olsen Aug. 21, 1951 2,621,203 Cope Dec. 9, 1952 2,698,336 Nelson Dec. 28, 1954 OTHER REFERENCES U. S. Naval Technical Mission Report 248-45 (1946), page 88. 

1. A PROCESS FOR TREATING A MIXTURE OF PARAFFIN WAX AND OXYGENATED HYDROCARBON COMPOUNDS OBTAINED AS RAFFINATE IN THE SOLVENT EXTRACTION FOLLOWING OXIDATION OF PETROLEUM WAX WHICH COMPRISES, ADSORBING THE MIXTURE ON ACTIVATED CARBON, DESORBING THE CARBON AND ADSORBED MATERIAL IN A FIRST STAGE DESORPTION WITH A LOW BOILING NON-POLAR, HYDROCARBON SOLVENT, RECOVERING A DESORBATE FROM SAID FIRST STAGE DESORPTION AND SEPARATING THEREFROM A PRODUCT POORER IN OXYGENATED HYDROCARBON COMPOUNDS THAN THE ORIGINAL MIXTURE, DESORBING THE CARBON AND ADSORBED MATERIAL IN A SECOND STAGE DESORPTION WITH A POLAR SOLVENT SELECTED FROM THE GROUP CONSISTING OF METHYL ETHYL KETONE, CHLOROFORM AND PYRIDINE, RECOVERING A DESORBATE FROM SAID SECOND STAGE DESORPTION AND SEPARATING THEREFROM A PRODUCT RICHER IN OXYGENATED COMPOUNDS THAN SAID ORIGINAL MIXTURE. 